1. Field of the Invention
The present invention generally relates to a brush scrubbing apparatus, and more particularly, the present invention relates to the brush scrubbing apparatus for a semiconductor wafer.
This application is a counterpart of Japanese application Serial Number 57166/1998, filed Mar. 9, 1998, the subject matter of which is incorporated herein by reference.
2. Description of the Related Art
In general, a conventional brush scrubbing apparatus has been used for scrubbing a semiconductor wafer. The conventional brush scrubbing apparatus has been disclosed in "SILICON WAFER HYOMEN NO KURINKA-GIJYUTU, KENJI SUGIMOTO et al, REALIZE INC, pp. 293-294", and Japanese Patent Laid Open No.8-206617.
In the conventional brush scrubbing apparatus, a rotating brush pushes to the surface of the semiconductor wafer and moves along it while a cleaning solution such as deionized water is supplied to the rotating brush. As a result, the conventional brush scrubbing apparatus removes particles hydrodynamically while the rotating brush rubs the surface of the semiconductor wafer.
More particularly, the conventional brush scrubbing apparatus retains the semiconductor wafer on a rotating turntable. The semiconductor wafer turns on a vertical axis while the deionized water is supplied to the surface of the semiconductor wafer. In this circumstances, a rotating brush mounted on a bottom portion of an arm, which moves above the semiconductor wafer, then contacts the surface of the semiconductor wafer via the dieionized water, and then is thrust toward the surface of the semiconductor wafer. And then the rotating brush moves along the surface of the semiconductor wafer. As a result, the conventional brush scrubbing apparatus removes particles.
In the conventional brush scrubbing apparatus, the brush is thrust downward a predetermined distance from a reference position of brush, which influences a cleaning effect and may cause damage to the semiconductor wafer. The reference position is a position that the rotating brush contacts the surface of the semiconductor wafer. The reference position is set with an eye measurement. When adjusting the predetermined distance, it is important to set the reference position precisely.
In the conventional brush scrubbing apparatus, it is desirable to precisely get the reference position for deciding the predetermined distance without using the eye measurement.